Research On Rapid Reactive Power Compensation System For Impact Load

The impact load introduced in the low-voltage distribution network of small and medium-sized enterprises is increasing day by day,which leads to serious lack and frequent fluctuations of reactive power,the power factor is low.Therefore,a rapid reactive power compensation system for impact load is presented and researched in this thesis,with the support of 2014 Hubei Technology Project(2014BAA011).The compensation system is consist of the reactive power grading adjustment subsystem and the reactive power continuous adjustment subsystem.The reactive power adjustment subsystem can compensate basically,and the reactive power continuous adjustment subsystem can compensate accurately and rapidly.The compensation system can meet the needs of compensation capacity at the same time to achieve fast compensation,improve the power factor.The main work accomplished and the results in this study are as follows:(1)The topological structure of the rapid reactive power compensation system for impact load is designed.The compensation system is consist of the reactive power grading adjustment subsystem and the reactive power continuous adjustment subsystem.And then these subsystem mechanisms are analyzed.Finally,the coordinated control method of the system is proposed.The research results lay the foundation for the application of the compensation system(2)The simulation research of the rapid reactive power compensation system for impact load is completed.Firstly,the simulation model of the system is constructed by MATLAB/Simulink simulation tool.The main modules of the system are designed.The system simulation schemes are proposed.The simulation schemes are including the impact load simulation scheme,the reactive power grading adjustment subsystem simulation scheme,the reactive power continuous adjustment subsystem simulation scheme and the coordinated control method simulation scheme.Finally,the simulation data and waveform are analyzed.The simulation results of these scheme verified the rapidity and accuracy of the compensation system.After the compensation,the reactive power of the system is greatly reduced and the trend of steady change is maintained.The power factor reaches and stabilizes at the target value.These research results lay the technical foundation for the design of the compensation system.(3)The scheme of the rapid reactive power compensation system for impact load is designed.The main circuit,operating circuit,the hardware and software of the control system are designed according to the topology of the compensation system.The hardware of the control system is designed with S7-200 PLC as its controller,including the hardware configuration,I/O circuit,power detection circuit and drive circuit.The software design of the control system includes PLC control plan and the host computer man-machine interface.The host computer man-machine interface is designed by configuration software MCGS.These research results lay the foundation for the realization of the prototype and its industrialization process.The compensation system can not only be applied to the low-voltage distribution network of small and medium-sized enterprises with the impact load,but also can be reconstructed according to the actual situation of the enterprise.The existing reactive power compensation device is used in conjunction with the designed system to meet the needs of enterprises under different production conditions,with practical application value and to reduce the cost of the enterprise.The system is expected to be applied in middle-small enterprises in the promotion and application.